Centrifuge



c. 1 AMER@ Oct. 15, 1968 CENTR IFUGE Filed Nov. 9, 1966 United StatesPatent O 3,405,866 CENTRIFUGE Clifford Leonard Amero, East Walpole,Mass., assignor to Bird Machine Company, South Walpole, Mass., acorporation of Massachusetts Filed Nov. 9, 1966, Ser. No. 593,163 8Claims. (Cl. 233-14) ABSTRACT OF THE DISCLOSURE The disclosure concernsa centrifuge of the rotary bowl type wherein the slurry and anotherfluid such as a ilocculant are separately fed into one end of the bowlby feed means which discharge'the respective fluids into separatecompartments from which they are fed into the bowl. The compartments arerotatable about the feed means and are separated longitudinally of thebowl axis by a splash baille which has a clearance from the feed meansthrough which slurry fed to one compartment may splash into the other.To eliminate fouling of the other iluid and its outlet to the bowl bysuch splashing slurry there is disclosed a chamber located within thecompartment for the other iluid which receives such fluid and dischargesit to the bowl' through one or more conduits removably attached to thechamber and extending through the compartment wall. The chamber isspaced axially of the bowl from the splash baille and radially of thebowl from its compartment outer wall to provide space to receivesplashing slurry which is discharged therefrom to the bowl. The chamberis removably mounted on an end wall of its compartment and has afrusto-conical end facing the bafile with its base closest to thebaille, with a central sleeve surrounding the feed means.

This invention relates to centrifugal separators in which the slurry anda secondary fluid y(e.g. washwater or ilocculant) are separately fedinto separate feed compartments located inside of a rotating bowl, andthen pass radially outwardly into the bowl.

In such centrifuges, the feed compartments are usually located in arotary member, such as the hub of a conveyor rotating at a differentialspeed to that of the bowl, which rotates relative to the feed pipes tothe compartments, these being normally stationary and extending into thebowl from one end. VTo completely isolate the separate compartmentswouldV therefore require a rotary seal in a wall between themsurrounding the stationary feed pipes. Such seals are not only expensivebut when exposed to splashing slurry feed are likely to becomecontaminated and to foul. The practice has therefore been to provideonly a splash baille or shield between the compartments with clearancearound the feed pipes. Slurry splashing through this clearance not onlycontaminates the secondary iluid but also in time plugs the feedoutlets, normally small diameter pipes, from the secondary feedcompartment. This necessitates stopping and dismantling the machine toclean the plugged outlets.

A primary object of the invention is to provide such a centrifugalseparator in which, without rotary seals, the feed of secondary fluidthrough its compartment to the bowl is so effectively shielded from theslurry that contamination of the secondary iluid with slurry andplugging of its feed outlets are prevented. Other objects are to providesuch secondary iluid feed apparatus that is reliable, easily installedand serviced, and low in cost.

In general, the invention features a main feed compartment into whichthe slurry is initially fed; a secondary feed compartment spaced axiallyalong the bowl from the main compartment; a splash baille, locatedbetween the feed compartments and having a feed conduit openice ing; asecondary fluid chamber located inside the secondary feed compartment,having a secondary iluid feed conduit opening, and spaced at least inpart from the wall of the secondary feed compartment and from the bailleto provide ilow space radially outwardly of the chamber opening forslurry that splashes through the splash baille; and at least one conduitcommunicating between the bowl and the secondary iluid chamber andpassing through the wall of the secondary feed compartment. The wall ofthe secondary feed compartment is provided with one or more outlets todrain slurry that splashes from the main compartment through the splashbaille into the flow space. In preferred embodiments the conduit betweenthe chamber and the bowl passes through an enlarged opening in thesecondary feed compartment wall, to provide the drainage for splashedslurry, the secondary iluid chamber is removably mounted in thesecondary feed compartment, preferably on a radial baille adjacent oneend of the secondary compartment, and the conduit or conduits areremovably secured to the chamber wall.

Other objects, features, and advantages will appear from the followingdescription of a preferred embodiment of the invention, taken togetherwith the attached drawings thereof, in which:

FIG. l is a side view partly broken away and partly in section, of aseparator embodying the present invention; and

FIG. 2 is a section taken along 2-2 of FIG. l.

In the illustrated embodiment, separator bowl 10 is supported at itsends by hollow shafts 11, 12 respectively journaled in bearing supports14, 1-6, shaft 11 being removably connected to bowl 10 by disc 10bfastened thereto by bolts 15. Conveyer 17, including helical blade 18mounted on generally cylindrical hub 19, is rotatably supported insidebowl 10 on shafts 20, 22 respectively journaled within shafts 11, 12.Shafts 11 and 20 are coupled through gear unit 26 so that when shaft 12is driven by a belt (not shown) through sheave 28, the bowl and conveyerwill rotate at slightly different speeds.

Slurry feed pipe 34 extends axially inside conveyer hub 19. A feed pipe40 for a secondary fluid, in this case flocculant, surrounds pipe 34.Liquid eilluent pipe 42 surrounds and is eccentrically mounted forrotation at its forward end on pipe 40. Liquid skimmer assembly 44 ismounted at the forward end of pipe 42 and includes skimmer 46 whichextends radially outwardly from the bowl axis into annular enlargement48 of hub 19. The other end of eilluent pipe 42 extends into a worm geararrangement (not shown) in bearing assembly 36, which allows pipe 42 tobe rotated while the machine is in operation, thereby, by virtue of theeccentric mounting, to change the radial position with respect to thebowl axis of skimmer 46. Liquid enters hub enlargement 48 throughopenings 50 to be scooped up by skimmer 46. Further details of a skimmerassembly and eccentric mounting of this type are disclosed in U.S.Patent 3,279,687.

Radial bailles 52 and 54 deilne main feed compartment 56 and secondaryfeed compartment 5S inside hub 19. Batlle 52 acts as a splash baille andhas opening 60 through which feed pipe 34 passes. Slurry fed throughpipe 34 enters the bowl through holes 62 in the conveyor hub. Secondaryiluid chamber 64 is removably bolted by Wall 66 to baille 54 andincludes cylindrical wall 68 of diameter less than that of the conveyerhub, frusto-conical wall at its end nearest splash baille 52, and asleeve 72 passing axially through wall 70 to define opening 74 throughwhich pipe 34 passes, the sleeve and wall together eilectivelypreventing slurry from entering chamber 64. Flocculant feed pipe 40enters through wall 66 and terminates inside chamber 64 and has adischarge opening 65 into said chamber. Four radial pipes S0 extend fromchamber 3 64 through enlarged holes 82 in hub 19 into the bowl, thesepipesbeing removably mounted on the chamber by screw threaded ends 81received in threaded apertures 83 in wall 68 of the chamber. By thisarrangement chamber 64 may, after removal of pipes 80 therefrom, bereadily separated bodily from the conveyer for cleaning or repair.

Bowl 10 has a frusto-conical portion 10a, leading to solids dischargechamber 84 and outlet pipe 86.

In operation, slurry is fed through pipe 34 into compartment 56'andthrough openings 62 into the bowl. Centrifugal action produces aradially outermost layer of solids that moves along the bowl wall underthe action of conveyer 17 toward and out openings 85. The radiallyinward layervof retained liquid is scooped up by skimmer 46 and passesout through pipes 42, 42a. Flocculant is fed through pipe 40 intochamber 64 and hence into the slurry in the bowl through pipes 80. Anyslurry that splashes from compartment 56 through opening 60 in splashbaffle 52 tends to be thrown radially outwardly, to enter the ow spacebetween wall 68 of chamber 64 and hub 19, and to pass into the bowlthrough enlarged openings 82. Wall 70 and sleeve 72 effectively preventthe slurry from entering chamber 64.

Other embodiments will occur to those skilled in the art and are withinthe following claims:

1. In a centrifugal separator comprising a rotatable bowl, means forfeeding slurry and another fluid separately into said bowl from one endthereof, main and secondary feed compartments for initially receivingand thereafter discharging into the bowl said slurry and other fluidrespectively, said compartments being mounted Within the bowl forrotation about said feed means, and a splash baille between said feedcompartments and spaced radially of the bowl from said feed means, thecombination of a secondary fluid chamber located inside said secondaryfeed compartment communicating with said feed means for receiving saidother fluid from said feed means, said chamber spaced axially of thebowl from said bathe and spaced radially of the bowl from the outer wallof said secondary feed compartment to provide space in said secondarycompartment external to said chamber for receiving slurry splashing fromsaid main compartment through the space between said baffle and saidfeed means;

at least one conduit extending from said chamber and through saidsecondary compartment outer wall for discharging said other lluid fromsaid chamber into said bowl; and

at least one outlet in said secondary compartment outer wall fordraining slurry received in said compartment into the bowl.

2. The separator according to claim 1 wherein said outlet comprsesanaperture in saidcompartment Outer wall through which passes a saidconduit, said aperture being substantially larger than thel outerdiameter of said conduit.

3. The separator according to claim 1 further including a conveyerrotatably mountedwithin the bowl for rotation 'relativeetheretoaboutvthe bowl axis, said conveyer having `a generally cylindricalfhubcomprising said compartments and forming saidfouterwalliof said`secondary feed compartment.'4 Y j 4. The separator'accordig to'claim 3lwherein the end of said chamber nearer said V`splash'baflle is providedwith a wall closely surrounding a portion ofvsaidfeed means. 5. Theseparatoraccording to`clain'1 4 wherein said chamber end wall isfrusto-conical with its base nearer said baie and is provided centrallytoward the apex with a sleeve surrounding said portion of said feedmeans.

6. The separator according to-claim 1 wherein'said secondary compartmentis provided with an end wall spaced longitudinally of the bowl axis fromsaid baffle', said chamber is removably mounted on said end wall andeach said conduit is removably secured to said chamber. Y

7. A centrifugal separator comprising a rotatable bowl;

Ymeans for feeding slurry and another fluid separately into said bowl;

a member mounted in saidv bowl and having a wallrotatably surroundingsaid feed means to provide a zone to initially receive and thereafterdischarge into the bowl said slurry; f v l a chamber located inside saidmember and surrounded by said wall for receiving said other fluid fromsaid feed means, said chamber being spaced radially from said wall toprovide space in 'said member external to said chamber, said space beingin at least partial communication with said zone for receiving slurrysplashings; and l f at least one conduit yc extending from said chamberand through said wall for discharging said other uid from said chamberinto -said bowl.

8. The separator of claim 7 wherein said chamber is removably mounted insaid member and said conduit iS removably secured to saidchamber. f 1

-References Cited UNITED STATES PATENTS 2,578,456 12/1951 Smith 233-14XR `2,670,131 27/ 1954 Ried 233-14 2,685,369 8/1954 Crossley 233-14 XR2,711,854 6/1955- Kjellgren 233-7 3,228,594 l/1966 Amero 233-7 HENRY T.KLINKSIEK, Primary Examiner.

